Apple buys many components for its devices from Chinese suppliers. Now, it's getting more aggressive about selling those devices in the world's largest cell phone market, inking a deal to sell iPhones through No. 1 wireless operator China Mobile, which could substantially boost Apple's earnings.

Positive earnings outlooks among some of Japan's major companies continued to boost investor sentiment. Japan's Nikkei 225 Index added 0.4% to close at 10,636. Hong Kong's Hang Seng slid 0.3% to end the day at 23,484. Markets in China remained closed for Chinese New Year.

When Apple first entered China with its wildly popular iPhone, the response was warm but not overly so. The iPhone 4, however, is off to a gangbuster start. If Apple can keep tapping China's potential, fervent shareholders could become even more bullish.

Until now, the iPhones sold in China did not have WiFi capabilities. But this is soon to change. A government ban on WiFi has been lifted and as early as next week, China Unicom, Apple's carrier partner, plans to roll out eight-gigabyte iPhones with third-generation service and WiFi throughout the country.

Research-In-Motion's Blackberry is under pressure in the U.S. from rivals like the iPhone. So its plans to move quickly into China, the world's top mobile market, may have caused its stock to spike recently. But can the Blackberry succeed in China?

Google's stand against China's censorship could draw retribution, damaging its nascent mobile efforts there. China Unicom, with 200 million subscribers, said it's scrubbed Google search from the company's phones. Will China Mobile, with 500 million users, be next? Both companies have close ties to the government.

Google co-founder Sergey Brin has emerged as the key force behind the search giant's decision to close its China-based search engine, citing his experience growing up in the Soviet Union. Google may suffer in the long run, but in this case, Brin has put principle above profit.

China's regulations meant that no Wi-Fi-enabled consumer devices could be sold legally in the world's most populous nation, so Apple disabled the Wi-Fi on iPhones it marketed there. But the rules have changed, and Apple and its partner, China Unicom, are moving to take advantage.